Sulfuric Acid → 6-Methoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline

HRID 54666Notes

Reaction equation

HRID 54666 reaction equation
[CH3:1][O:2][C:3]1[CH:23]=[CH:22][C:6]([CH2:7][NH:8][CH2:9][CH:10](O)[C:11]2[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[C:13]([O:19][CH3:20])[CH:12]=2)=[CH:5][CH:4]=1.S(=O)(=O)(O)O.C(Cl)(Cl)Cl.CO>FC(F)(F)C(O)=O>[CH3:1][O:2][C:3]1[CH:23]=[C:22]2[C:6](=[CH:5][CH:4]=1)[CH2:7][NH:8][CH2:9][CH:10]2[C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[C:13]([O:19][CH3:20])[CH:12]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 14719544HCID 14719544, compoundHCID 21584188Chloroform methanol

Product 1

HCID 147195466-Methoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinolineYield 88.2%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

α-[[(4-methoxybenzyl)amino]methyl]-3,4-dimethoxybenzyl alcohol (950 mg) was dissolved in 7.2 ml of trifluoroacetic acid, and after adding thereto 0.22 ml of conc. sulfuric acid under ice cooling, the reaction was allowed to react for 45 minutes. The reaction solution was concentrated, and subjected to azeotropic distillation with toluene 2 times. After adding chloroform, the mixture was basified by addition of 28% aqueous ammonia under ice cooling. By a separating procedure, the chloroform layer was collected, washed with water, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the residue obtained was subjected to silica gel column chromatography (chloroform-methanol-28% aqueous ammonia=15:1:0.1), giving 790 mg of 6-methoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline as oily matter.

Workup

  1. additionafter adding
  2. customto react for 45 minutes
  3. concentrationThe reaction solution was concentrated
  4. distillationsubjected to azeotropic distillation with toluene 2 times
  5. additionAfter adding chloroform
  6. additionthe mixture was basified by addition of 28% aqueous ammonia under ice cooling
  7. customBy a separating procedure, the chloroform layer was collected
  8. washwashed with water
  9. dry with materialdried over anhydrous sodium sulfate
  10. distillationThe solvent was distilled off
  11. customthe residue obtained

Sources & evidence

ORD record
ord-6c7c01772e5f4b4da26f581c38bfa7b8
Source dataset
uspto-grants-1997_04
Patent number
US05623074

Reaction notes

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